“Brett McGurk, who I do not know, was appointed by President Obama in 2015,” Trump said Saturday on Twitter. “Was supposed to leave in February but he just resigned prior to leaving. Grandstander? The Fake News is making such a big deal about this nothing event!”

Trump’s tweet raised questions about his awareness of or interest in the intricate policies surrounding one of his cornerstone campaign promises — the defeat of the Islamic State, in which McGurk played a central role in Washington, Baghdad and elsewhere.

It “would be an indictment of the president himself had he not met the individual coordinating the international coalition against the Islamic State,” a former senior defense official who worked closely with McGurk told The Washington Post.

White House press secretary Sarah Sanders did not respond to a request for comment about whether and when Trump was briefed by McGurk himself or whether Trump was provided reports or briefings prepared by the envoy.

The State Department replied to a request for comment with a message saying the press office was operating in a “reduced status” because of the government shutdown.

The fallout over McGurk’s departure and the Syria withdrawal brought sharp rebukes from former officials and some conservatives. “Why don’t you know the man who has done more than any civilian to degrade ISIS?” Susan E. Rice, President Barack Obama’s national security adviser and U.N. ambassador, wrote on Twitter.

McGurk has been described by current and former officials as tirelessly dedicated and respected by militia commanders and ambassadors alike, and his commanding expertise was sought and deferred to within the U.S. government. His involvement at high levels in government and diplomatic circles signaled a trusted presence in the coalition since his appointment as envoy by Obama.

His work in the Middle East started under President George W. Bush and spanned three administrations. That experience is perhaps without equal, Derek Chollet, a former U.S. assistant secretary of defense in the Obama administration, told The Post.

“George W. Bush and Barack Obama knew and respected Brett and considered him one of their most important advisers,” Chollet said. Trump has shown evidence of disengagement from policy and a disregard for expertise, he said, “and it’s very telling that Donald Trump claims to have never heard of him.”

Brett McGurk, left, and Rupert Jones, deputy commander of Combined Joint Task Force Operation Inherent Resolve, arrive for a meeting with the Raqqa Civil Council in the northern Syrian village of Ain Issa. (Delil Souleiman/AFP/Getty Images)

McGurk was a chief architect of Bush’s troop surge in Iraq and had a senior role in negotiating the 2011 U.S. withdrawal from Iraq for Obama. That experience carved out trust with Iraqi leaders, Chollet said, which spurred several postings that eventually led to the envoy appointment.

In the Syria campaign, he was the driving force behind the creation of the Syrian Democratic Forces. His tenacity and personal touch in building relationships served the counter-Islamic State effort well, colleagues told The Post.

McGurk met face-to-face with Kurdish and Arab leaders of the SDF and was a continual presence in Baghdad and Irbil, the capital of the autonomous Kurdish region in northern Iraq, becoming the most recognizable American official in the country at a time when an Islamic State blitz threatened both capitals.

Aside from Mattis’s resignation, the most significant factor in McGurk’s decision was an inability to reconcile the president’s decision with his experience as the U.S. diplomat who “spent time with the guys on the ground who have been fighting and dying,” including Kurdish fighters in Syria, said an official familiar with his views. “To just suddenly, in one split second” have to tell them the United States was leaving “is hard to face.”

Robert Ford, the former ambassador to Syria who worked closely with McGurk, told The Post he agreed with Trump’s decision but said the National Security Council did a “lousy job” articulating Trump’s desire to leave Syria after largely eradicating the Islamic State, though fighters remain.

Earlier this month, McGurk said in a briefing that defeating the physical caliphate is just one phase of a “much longer campaign.”

On Monday, Trump recalled some details about McGurk, only to attack him.

It is unclear how the United States will manage its military presence in Syria in the coming weeks and months or whether Special Operations troops will assume a greater role in flushing out remaining pockets of militants there.

The U.S. military may also keep supplying SDF forces and launch airstrikes against Islamic State fighters — efforts that would probably be complicated by a reduced American presence.

But any action that requires partner forces risking their lives may be viewed with skepticism after the fallout with McGurk, said the former senior defense official who worked with him.

“Our commitment is only as good as the president’s next tweet,” the former official said.

As one of the the Americans most directly affected by what @realDonaldTrump refers to here, and as a journalist who has done much reporting on what actually happened, I can say w/ a high level of confidence that the president's account is wholly inaccurate, probably purposely so. https://t.co/ySgWeYWvPV

Alex HortonAlex Horton is a general assignment reporter for The Washington Post. He previously covered the military and national security for Stars and Stripes, and served in Iraq as an Army infantryman. Follow

John HudsonJohn Hudson is a national security reporter at The Washington Post covering the State Department and diplomacy. He has reported from a mix of countries including Ukraine, Pakistan, Malaysia, China, and Georgia. Follow

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